Thursday, August 12, 2010


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When your mind drifts, it's hard to remember what was going on before you stopped paying attention. Now a new study has found that the effect is stronger when your mind drifts farther – to memories of an overseas vacation instead of a domestic trip, for example, or a memory in the more distant past.

Psychologists have known for a while that context is important to remembering. If you leave the place where a memory was made – its context – it will be harder for you to recall the memory. Previous studies had also found that thinking about something else – daydreaming or mind-wandering – blocks access to memories of the recent past. Psychological scientists Peter F. Delaney and Lili Sahakyan of the University of North Carolina at Greensboro and Colleen M. Kelley and Carissa A. Zimmerman of Florida State University wanted to know if the content of your daydreams affects your ability to access a recently-acquired memory.

For one experiment, each participant looked at a list of words as they appeared on a computer screen, one at a time. Then they were told to think either about home – where they'd been that morning – or about their parents' house – where they hadn't been in several weeks. Next, the participant was shown a second list of words. At the end of the test, they had to recall as many of the words from the two lists as possible. Participants who had thought about the place they'd been only a few hours before remembered more of the words from the first list than did participants who had thought back several weeks. The same was true for memories about place, tested in a second experiment. Those who thought about a vacation within the U.S. remembered more words than those who thought about a vacation abroad. The study is published in Psychological Science, a journal of the Association for Psychological Science.

One practical application of the research might be for people who want to forget about something. "If there's something you don't feel like thinking about, you're better off remembering a more distant event than a close event, to try to put it out of your mind for a while," says Delaney. "It can help you feel like you're in a different situation."

Psychological Science


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A new packing material that grows itself is now appearing in shipped products across the country.

The composite of inedible agricultural waste and mushroom roots is called Mycobond™, and its manufacture requires just one eighth the energy and one tenth the carbon dioxide of traditional foam packing material.

And unlike most foam substitutes, when no longer useful, it makes great compost in the garden.

The technology was the brainchild of two former Rensselaer Polytechnic Institute undergraduates, Gavin McIntyre and Eben Bayer, who founded Ecovative Design of Green Island, N.Y., to bring their idea into production.

"We don't manufacture materials, we grow them," says McIntyre. "We're converting agricultural byproducts into a higher-value product."

Because the feedstock is based on renewable resources, he adds, the material has an economic benefit as well: it is not prone to the price fluctuations common to synthetic materials derived from such sources as petroleum. "All of our raw materials are inherently renewable and they are literally waste streams," says McIntyre. "It's an open system based on biological materials."

With support from NSF, McIntyre and Bayer are developing a new, less energy-intensive method to sterilize their agricultural-waste starter material--a necessary step for enabling the mushroom fibers, called mycelia, to grow. McIntyre and Bayer are replacing a steam-heat process with a treatment made from cinnamon-bark oil, thyme oil, oregano oil and lemongrass oil.

The sterilization process, which kills any spores that could compete with Ecovative's mushrooms, is almost as effective as the autoclaving process used to disinfect medical instruments and will allow the Mycobond™ products to grow in the open air, instead of their current clean-room environment.

"The biological disinfection process simply emulates nature," says McIntyre, "in that it uses compounds that plants have evolved over centuries to inhibit microbial growth. The unintended result is that our production floor smells like a pizza shop."

Much of the manufacturing process is nearly energy-free, with the mycelia growing around and digesting agricultural starter material--such as cotton seed or wood fiber--in an environment that is both room-temperature and dark. Because the growth occurs within a molded plastic structure (which the producers customize for each application), no energy is required for shaping the products.

Once fully formed, each piece is heat-treated to stop the growth process and delivered to the customer--though with the new, easier, disinfection treatment, Bayer and McIntyre are hoping the entire process can be packaged as a kit, allowing shipping facilities, and even homeowners, to grow their own Mycobond™ materials.

Based on a preliminary assessment McIntyre and Bayer conducted under their Phase I NSF SBIR award, the improvements to the sterilization phase will reduce the energy of the entire manufacturing process to one fortieth of that required to create polymer foam.

"This project is compelling because it uses innovative technology to further improve Ecovative's value, while also providing the environmental benefits that NSF is looking for," said Ben Schrag, the NSF program officer who oversees Ecovative's Small Business Innovation Research (SBIR) award. "The traction that they have gotten with their early customers demonstrates how companies can build strong businesses around products whose primary competitive advantage lies in their sustainability."

In addition to the packaging product, called EcoCradle™, Ecovative has developed a home insulation product dubbed greensulate™. Comparable in effectiveness to foam insulation, it is also highly flame retardant.

Ecovative is already producing custom protective packaging products for several Fortune 500 companies, though they are leveraging the new disinfection process to produce turnkey systems that they plan to deploy to off-site customers and do-it-yourself homeowners by 2013.

(Photo: Edward Browka, Ecovative Design)

National Science Foundation


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Climate change has affected winds over the Southern Ocean and reduced the amount of carbon that oceans absorb to slow global warming – a vicious cycle that has been reproduced in a high-resolution computer model for the first time.

According to a paper published in Nature earlier this year, Takamitsu Ito, an oceanographer at Colorado State University, and collaborators at Massachusetts Institute of Technology and Scripps Institution of Oceanography successfully simulated the carbon cycle of the Southern Ocean at a very high resolution using one of the world’s most powerful computers at NASA. The sheer size, remoteness and severe weather conditions surrounding the Antarctic continent prevent scientists from collecting enough data on site, so they must rely on computer simulations. The Southern Ocean is filled with eddies that require massive computer power to mimic in modeling.

“Our result implies that climate change can significantly influence the global carbon cycle,” said Ito, who co-wrote the paper with graduate student Molly Woloszyn. “The model calculation demonstrated that changing atmospheric winds indeed control the transport of carbon dioxide within the ocean and potentially change the rate of oceanic carbon uptake."

“Changes in oceanic carbon sink, in turn, affect the atmospheric carbon dioxide and climate,” Ito said. “This circular argument – that carbon dioxide is the cause and consequence of climate change – indicates complex interplay that governs the long-term evolution of our planet. The oceans are the major sink of atmospheric carbon dioxide helping to slow down global warming.”

Ito added that the atmosphere overlying the Southern Ocean is undergoing significant climate change. The major causes of climate change – ozone depletion and global warming – are trends likely to continue for decades to come, he said.

Since spring 2008, Ito has received a $418,000 grant from NASA and a $113,000 grant from NOAA to develop a high-resolution carbon cycle model of the Southern Ocean and turn the theory into practical suggestions for strategies to detect climate change impacts. The research contributes to the societal needs for predicting carbon sources and sinks and future atmospheric carbon dioxide concentrations.

Each year, the world’s oceans absorb about 2.2 billion metric tons of carbon generated by human activity. About 40 percent of oceanic carbon uptake happens in the Southern Ocean.

“We are concerned about this region because the carbon sink is large enough to impact the global carbon balance,” Ito said. “The rate at which the oceans absorb carbon from the atmosphere depends on a number of processes including atmospheric winds, heat content, ocean currents, sea ice and other factors in the ecosystem.”

(Photo: Colorado State U.)

Colorado State UniversitY


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Our personalities play a role in every aspect of our lives, from friendships to hobbies, from whom we marry to what we do for a living.

It’s only natural, then, that personality should also play a role in our political beliefs and behavior, says Jeffery Mondak – yet it’s long been ignored as a subject of study.

Until very recently, this is.

In one of the first books on the subject, Mondak, a University of Illinois professor of political science, makes the case that certain personality traits can sway us to be more liberal or conservative, to be more or less likely to attend a protest march, more or less likely to ignore politics altogether.

With the understanding that we’re born with most of those traits, that means we’re born with certain political tendencies, said Mondak, the James M. Benson Chair in Public Issues and Civic Leadership. And knowing that, he thinks, could make a difference in everything from how political campaigns are run to our view of the partisan shoutfest.

His conclusions in “Personality and the Foundations of Political Behavior” (Cambridge University Press) come from more than 13 years of study at the intersection of psychology and politics, and draw on his own research and that of others.

“We’ve had decades of research on political participation where we’ve not even acknowledged the possibility that people have basic psychological tendencies,” said Mondak, who also is a faculty affiliate of the university’s Cline Center for Democracy.

Instead, political scientists have explained political behavior almost exclusively by looking at aspects of people’s environment, such as where they live, their incomes, years of schooling, or their life experience, Mondak said.

People have been considered “blank slates” who were “identical at the moment of birth, or identical at the moment that they first encountered politics,” he said.

Those environmental factors do matter, but they are not the whole story, Mondak said.

Extroverts, for instance, are much more likely to participate in political activities that involve direct interaction with other people, such as marches, rallies, protests, and door-to-door canvassing, Mondak said. They’re no more likely, however, to give money or display a bumper sticker, he said.

People who are more responsible or conscientious are more likely to show up for jury duty but actually less likely to vote, Mondak said. It may be the non-voters among this group have thought carefully about it, believe they can make little difference, and so have decided politics is not worth their time, he said.

Those who rank high in their openness to experience are very likely to be liberal, even more so if they’re also low in conscientiousness, Mondak said. Those high in conscientiousness are very likely to be conservative, even more so if they’re also low in their openness to experience.

Personality may also explain why research on the effects of negative advertising has produced contrary findings, Mondak said. Rather than making everyone more or less likely to vote, it could be that negative ads motivate some and turn off others, he said.

Mondak’s research is based around a breakthrough in the psychological study of personality going back about two decades, known as the “five factor” or “Big Five” approach. It provides a structure for grouping what were hundreds of personality traits under five broad dimensions: openness to experience, conscientiousness, extroversion, agreeableness and neuroticism (or emotional stability).

Numerous psychological studies have served to reinforce this approach, giving researchers a practical tool for collecting information about personality traits along with other information, Mondak said. Surveys can now include a reasonable five or 10 questions related to personality, whereas it previously would have required hundreds.

“We get a sense of the whole picture now because of the structure provided by these five broad-scale dimensions,” Mondak said.

Studying the connection between personality and politics could matter for a variety of reasons, one of them being the way we view political opponents and the extremes of today’s ideological food fights, Mondak said. “If we can grasp the fact that some people just behave differently, just think differently, or are just oriented differently than others, then I think that has the potential to promote understanding, and to me that’s a positive,” he said.

Also, political organizers might want to note that one size does not fit all when it comes to getting people involved, Mondak said. Not everyone wants to go to a protest rally, for instance. “And so if all they do is show up and ask you to go to the protest rally, you’re going to say no, and then you’re not engaged and then they’ve not benefited from your potential involvement.”

(Photo: L. Brian Stauffer)

University of Illinois


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One of the human body’s most powerful defensive tools, the blood-brain barrier is a chemical labyrinth that prevents toxins and viruses in the bloodstream from reaching the brain. This foolproof security system, however, limits the ability of physicians to deliver drugs directly to the brain, making it difficult to treat brain tumors.

Researchers at Rensselaer Polytechnic Institute are endeavoring to solve this problem by investigating new methods for bypassing the blood-brain barrier and combating the spread of brain cancer.

The research team, led by Pankaj Karande, assistant professor in the Department of Chemical and Biological Engineering, is particularly interested in developing treatments for diffuse malignant glioma, a lethal type of brain cancer for which there is currently no cure. He recently won a $100,000 grant from the Goldhirsh Foundation to further his study into this important topic.

“There are a number of good drugs available for treating glioma, but our problem is that getting any drug into the brain is a huge challenge,” Karande said. “Nature designed the blood-brain barrier to protect us from harm, and it’s very good at its job. When you attempt to treat patients with brain ailments, the blood-brain barrier recognizes most drugs as foreign molecules and keeps them out. We’re trying to develop a method to elegantly, safely, and reproducibly open up the blood-brain barrier, so we can introduce drugs into the brain.”

The blood-brain barrier is made up of protein-lined cells, which are layered together not unlike Velcro, Karande said. Generally, the only molecules that can pass through the barrier are certain nutrients and essential vitamins. His team is looking for a chemical “wedge” to pry a hole between layers, just large enough for drug molecules to breach the barrier and enter the brain. The hole would only stay open for a very short time, and then repair itself, thus posing very little risk of damage to the brain in the long term.

Using a combination of computer simulations, in-vitro modeling, molecular modeling, and microarray technology, the research team is designing new peptides — short chains of amino acids — that can serve as the needed “chemical wedge.”

“Currently, the best therapy for brain surgery involves removing the part of the brain that is malignant or tumorous. In the case of diffuse glioma, however, the cancer is so widespread that you can’t remove it — you’d have to remove, effectively, the entire brain,” Karande said. “If we are successful in breaching the blood-brain barrier and delivering drugs straight to the brain, it could have a tremendous impact in the fight against cancer, as well as other chronic conditions such as Alzheimer’s disease, Parkinson’s disease, epilepsy, and traumatic brain injury.”

Another research thrust of Karande’s is looking at non-invasive methods of delivering drugs and vaccines through the skin and into the bloodstream. The idea is for health care workers and diabetics to use small patches that can be directly applied to the skin, rather than piercing the skin with needles. Key findings of this study were published in 2004 in the journal Nature Biotechnology, and described a new method for using chemicals to make molecular-sized holes in skin through which drug molecules can travel. The method is safe and caused no inflammation, irritation, or long-term damage.

Karande said skin protects our bodies in a way that’s similar to how the blood-brain barrier protects our brains. Both are extremely complex and effective systems for safeguarding what’s inside.

“We have learned a lot about how to breach these biological barriers safely and effectively, so we can apply some of the principles we learned from opening up the skin to opening up the blood-brain barrier and going into the brain,” Karande said. “We are taking nature’s own cues. We know how nature forms these barriers, and what is necessary to form the junctions of the barriers, so we are using this understanding to figure out what is needed to break these junctions.”



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In the spring, later sunset and extended daylight exposure delay bedtimes in teenagers, according to researchers at Rensselaer Polytechnic Institute’s Lighting Research Center (LRC).

“Biologically, this increased exposure to early evening light in the spring delays the onset of nocturnal melatonin, a hormone that indicates to the body when it’s nighttime,” explains Mariana Figueiro, Ph.D., associate professor. “This extended exposure adds to the difficulties teens have falling asleep at a reasonable hour.”

Over time when coupled with having to rise early for school, this delay in sleep onset may lead to teen sleep deprivation and mood changes, and increase risk of obesity and perhaps under-performance in school, according to Figueiro.

“This is a double-barreled problem for teenagers and their parents,” says Figueiro. “In addition to the exposure to more evening daylight, many teens also contend with not getting enough morning light to stimulate the body’s biological system, also delaying teens’ bedtimes.”

The new findings detailing the impact of early evening light in spring on melatonin onset and sleep times have just been published in Chronobiology International by Figueiro and LRC Director Mark Rea, Ph.D. The study found that 16 eighth-grade students from Algonquin Middle School in upstate New York experienced a delay in melatonin onset by an average of 20 minutes measured in one day in spring relative to one day in winter. Melatonin levels normally start rising two to three hours prior to a person falling asleep. The students also kept sleep logs as part of the study, which collectively showed a 16-minute average delay in reported sleep onset and a 15-minute average reduction in reported sleep duration measured in one day in spring relative to one day in winter.

Patterns of light and dark are the main cues for synchronizing our internal biological clock with the 24-hour solar day. Daylight is rich in short-wavelength (blue) light, which maximally stimulates our biological clock. This internal clock is responsible for regulating the timing of our sleep and other daily biological cycles, called circadian rhythms.

The results of the Algonquin Middle School study demonstrated that it was the extended daylight hours due to the seasonal change, not evening electric lighting after dark in the home, that had the biggest impact on delayed sleeping patterns. According to Figueiro, these results underscore the importance of measuring the 24-hour circadian light and dark patterns in order to draw valid inferences from field studies of this kind.

“This latest study supplements previous work and supports the general hypothesis that the entire 24-hour pattern of light/dark exposure influences synchronization of the body’s circadian clock with the solar day and thus influences teenagers’ sleep/wake cycles,” explains Figueiro. “As a general rule, teenagers should increase morning daylight exposure year round and decrease evening daylight exposure in the spring to help ensure they will get sufficient sleep before going to school.”

In the study, the Algonquin Middle School students were exposed to significantly more “circadian light” in the early evening during spring than in winter, resulting in both delayed melatonin onset and shorter self-reported sleep durations. Each subject wore a Daysimeter, a small, head-mounted device developed by the LRC to measure an individual’s exposure to daily “circadian light,” as well as rest and activity patterns. The definition of circadian light is based upon the potential for light to suppress melatonin synthesis at night, as opposed to measuring light in terms of how it stimulates the visual system.

This study, sponsored by the U.S. Green Building Council (USGBC) and, in part, by a grant from a Trans-National Institutes of Health Genes, Environment and Health Initiative (NIH-GEI), is the first to relate field measurements of circadian light exposures to a well-established circadian marker (the rise in evening melatonin levels) during two seasons of the year.

In a previous field study, also funded by USGBC and NIH-GEI and published in Neuroendocrinology Letters, Figueiro and Rea examined the impact of morning light on teen sleep habits and found that removing short-wavelength (blue) morning light resulted in a 30-minute delay in sleep onset by the end of a five-day period.

(Photo: Rensselaer/Lighting Research Center)

Rensselaer Polytechnic Institute




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